Bond Order Formula

What is the Bond Order Formula?

Bond order is the number of bonds formed between the atoms interacting with each other. It is the measure of the stability of the molecule. The stability of the molecule also depends on the type of bonds. The electronic configuration of the atoms determines the bond order. There is a well-established bond order formula to calculate bond order. It is important to study the formula to find bond order to look into the structure of different compounds and calculate their stability. Let us learn more about bond orders in this chapter.


What is Bond Order Formula Structure?

The average bond order formula considers the number of electrons on the bonding and the antibonding orbitals. It is defined as half of the difference between them. The bond order equation is

Bond order = ½ [Nb-Na]

Where Nb is the number of electrons in the bonding orbitals

And Na is the number of electrons in the antibonding orbitals.

A simpler way to find the bond order is to calculate the number of bonds between the atoms. For example, for N≡N, the bond order is 3.  


How is a Bond Order Determined in a Chemical Reaction?

In a chemical reaction between two atoms, the bond order is determined by the number of electrons participating in bond formation. The atoms can interact to form covalent or ionic bonds. In Ionic bonds, electrons are transferred from one atom to another. Covalent bonds involve the sharing of electrons between two atoms. The electronic configuration of the atoms determines the bond order. For example, in a Carbon molecule, four bonds are shared between the two carbon atoms. Both the carbon atoms require four electrons to complete their octet. Therefore, the bond order in a carbon molecule is 4. Similarly, the bond order for nitrogen molecules is 3 and oxygen is 2.


What is the Importance of Bond Order?

It is important to study the bond order formula in chemistry. It helps us to understand several factors contributing to the formation of the compound. Some of them are:

  • Bond order helps us to know the number of participating electrons in the formation of bonds.

  • Bond order helps us to understand the stability of the bond. Higher bond order confers more stability.

  • Bond order helps us to understand the bond length.

  • Bond order helps us to understand bond strength. Higher bond order implies more energy is required to break the bond.

  • Bond order gives us an indication of the hybridization of the molecule.

  • A fractional bond order value implies that no bond is formed.

Conclusion

The concept of bond order has been studied for several years. Bond order is determined by the number of bonding and antibonding electrons. People use the bond order formula to find out the bond. Various properties of the bond can be known from bond order values.

FAQs (Frequently Asked Questions)

Q1. What is the Bond Order for the Electronic Configuration of a Compound = (σ2s)² (σ*2s)² n(2px)² n(2py)²?

The electronic configuration of the compound = (σ2s)² (σ*2s)² n(2px)² n(2py)²

Number of bonding electrons = 8

Number of antibonding electrons = 4

Therefore,

Bond order = (Nb – Na) / 2

       =( 8 – 4 )/ 2

                   = 2

Therefore, two bonds are formed between the atoms in the molecule.

Q2. What are the Major Factors Considered for the Calculation of Bond Orders?

The bond order formula considers two major parameters- the number of electrons in the bonding orbitals and the number of electrons in the antibonding orbitals.

Q3. What Can We Know about the Bond Properties from the Bond Order?

We will know about the number of participating electrons, bond stability, bond strength, bond length,  and an idea about the type of hybridization from the bond order value. If the bond order value is fractional, it implies that no bond is formed between the atoms.